Is Imperial Hellkite legal in Standard, Modern, and Commander?

Imperial Hellkite is legal in: Legacy, Vintage, Commander.

What type of card is Imperial Hellkite?

Imperial Hellkite is a Creature — Dragon. Its oracle text reads: "Flying Morph {6}{R}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, you may search your library for a Dragon card, reveal it, put it into your hand, then shuffle."